Rotary shaft seal types
SC oil seal: single lip, rubber-covered outside diameter
An SC seal is a single spring-loaded lip in a rubber-covered case, the plain oil seal for retaining oil or grease where the outboard side is clean. Conquest Seal supplies radial shaft seals, also sold as rotary shaft seals, rotary lip seals and oil seals, in inch and metric sizes. Send the part number or drawing and we quote it.
- Family
- Radial lip seals
- Designation
- SC
- Lips
- 1
- Dust lip
- No
- Garter spring
- Yes
- Outside diameter
- Rubber-covered
- Case
- single metal insert
- Pressure
- 0.3 bar (4.4 psi) (rated by NOK® for its standard types; not a pressure seal)
Radial lip seals
A flexible lip pressed against a rotating shaft by a garter spring, held in the housing by a case. This is what most people mean by an oil seal, and it retains lubricant at low pressure rather than holding pressure.
When to use it
Retaining oil or grease where the outboard side is clean. The bore is a split housing, a light alloy that expands with heat, or rough enough that a metal case would leak past it. The rubber outside diameter grips the bore roughness and seals against it.
When another type fits better
- TC: Sealing lip and dust lip, rubber-covered outside diameter, when there is dust or spray on the outboard side.
- SB: Single lip, metal outside diameter, when the bore must locate the seal precisely and there is no pressure.
A designation match is not a fit, form and function match. These schemes measure different things, and the same letter means different things in different catalogs. Confirm the three dimensions, the lip material and the duty against the drawing before substituting any seal.
| Letter code | ISO 6194-1 | JIS B 2402 | JASO | DIN 3760/3761 form |
|---|---|---|---|---|
| SC | Type 4 | TYPE 1 | S | A (our reading) |
Sources: NOK Oil Seals catalogue 014E, read 2026-09-16; Freudenberg Technical Manual for Simmerring® seals and rotary seals, read 2026-09-16; ISO 6194-1: Rotary shaft lip-type seals incorporating elastomeric sealing elements, Part 1: Nominal dimensions and tolerances, ISO 6194-1:2007, read 2026-09-27; JIS B 2402-1: Rotary shaft lip-type seals incorporating elastomeric sealing elements, Part 1: Nominal dimensions and tolerances, Japanese Standards Association, JIS B 2402-1:2013, read 2026-09-27.
NOK is a trademark of NOK Corporation; Simmerring is a trademark of Carl Freudenberg KG. The maker designations on this page are the makers' own. No affiliation or endorsement is implied.
Related pages
Orders are handled under Conquest Seal's AS9100D quality management system, whose certificate scope includes distribution.
Send the shaft, bore and width, or the old seal's markings
The three dimensions or the code printed on the old seal, the speed, any pressure, the fluid and the quantity. A Conquest representative replies with the quote.
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